Spence made the comment during a luncheon fundraiser in Springfield. He repeated it several times in a subsequent interview with The Associated Press, justifying his assertion at least partly by pointing to TV ads by the Democratic governor that Spence says are false and defamatory.

"If he's willing to trash my reputation to get re-elected when he knows that's not the truth ... that to me is selling your soul to the devil," Spence told the AP.

"Everyone knows campaigns can be stressful, but Dave Spence needs to pull himself together and get a grip," Shur said.

Spence had a packed campaign schedule Thursday, starting in Joplin and then attending about a half-dozen events in Springfield, including several with U.S. Sen. Roy Blunt, R-Mo. About 160 people were at the "Women for Spence" luncheon fundraiser, which featured introductory speeches by former state Auditor Margaret Kelly, Blunt and Spence's wife, Suzie.

At the fundraiser, Spence described Nixon as "somebody who has sold his soul to the devil to get re-elected."

Spence's remark about the devil came near the end of a speech in which he asserted that Missouri was falling behind economically and said Nixon has tried to take credit for private sector jobs he did not create. He also accused the governor of making decisions on appointments and bill signings based on financial contributions and "political payback" — an assertion that the Missouri Democratic Party previously denounced on Nixon's behalf.

In recent weeks, Spence has been upset by Nixon campaign ads that describe him a banker and say that Spence used part of a $40 million federal bailout to a bank to buy a vacation home for himself. Spence did once serve on the board of Reliance Bancshares, which received bailout money, and Spence did receive a home loan from the bank. But Spence said there was no connection to the federal money, he received no special treatment and he left the room when fellow board members considered and approved his home loan.

"To try to defame somebody else and slander somebody else, he's made a pact with the devil," Spence said in reference to Nixon's ad.

Spence said it is false to describe him as a banker, noting he owns only a small percentage of the bank. Spence made his fortune as a business owner and has since sold most of his share in Alpha Packaging, which manufactures plastic bottles for pharmaceuticals and personal care products. Spence said he still has a majority ownership in Legacy Pharmaceutical Packaging, which fills prescription bottles.

Shur said Thursday that Nixon's campaign stands by the ads about Spence's involvement with the bank.